Turbomachine

Abstract

A turbomachine has a turborotor made up of a shaft and a rotor disk, and an electric machine having an electric rotor. The rotor disk is arranged at one end of the shaft, in overhung manner, and the electric rotor is connected with the shaft of the turborotor. The electric rotor is arranged on the other end of the shaft, also in overhung manner, and the shaft is mounted on shaft bearings in a bearing housing that thermally separates the shaft bearings from the electric machine.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]Applicant claims priority under 35 U.S.C. §119 of German Application No. 103 10 677.4 filed Mar. 12, 2003.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a turbomachine having a turborotor made up of a shaft and a rotor disk, and an electric machine having an electric rotor, whereby the rotor disk is arranged at one end of the shaft, in overhung manner, and whereby the electric rotor is connected with the shaft of the turborotor.[0004]2. The Prior Art[0005]In the case of the turbomachines known from practice, having the characteristics described initially, the shaft is mounted on both sides of the electric rotor. This turborotor configuration makes great demands on the required production precision of the bearing holder bores. These demands particularly become significant when using fast-running high-precision roller bearings, which demand an alignment accuracy of the bearings relative to o...

AI Technical Summary

Benefits of technology

[0006]It is an object of the present invention to configure a turbomachine having the characteristics described initially, so that great alignment accuracy between the shaft bearings can be assured in thermally stressed operation. Furthermore, the electric rotor should be readily accessible.

[0007]These objects are accomplished, according to the invention, by arranging the electric rotor on the other end of the shaft, also in overhung manner, and by mounting the shaft on shaft bearings in a bearing housing that thermally separates the shaft bearings from the electric machine. In this connection, the shaft bearings and the bearing housing form a sealed unit. Therefore the bearing holder bores can be produced in a single chucking process. This arrangement allows a very great production precision with little effort. The turborotor therefore has a high level of running accuracy and low bearing friction. Because of the thermal separation of the shaft bearings from the electric machine, according to the invention, thermally induced stresses and geometrical changes in the bearings are reduced. In this connection, the bearing housing according to the invention represents effective protection against the heat development in the air gap between the rotor and the stator of the electric machine, which can be significant, in part. However, the arrangement according to the invention is also advantageous in connection with the occurrence of very low temperatures, particularly at cryogenic temperatures, which occur, for example, in connection with the operation of the turbomachine in a liquefaction plant. In total, the encapsulation of the shaft bearings in the common bearing housing further increases the running accuracy of the turborotor, and further reduces the bearing friction. Furthermore, the electric rotor is easily accessible from the face of the rotor, without parts of the shaft bearing having to be disassembled. This accessibility allows easy installation and removal of the rotor, for example.

[0009]Preferably, the bearing housing has shaft ducts for the shaft of the turborotor, which are provided with heat insulation, in order to further increase the thermal protection of the shaft bearings. In addition, the shaft segments between the bearing housing and the rotor disk, i.e. the rotor, can be provided with additional insulation rings, in order to further increase the protective effect. Preferably, the shaft bearings are configured as high-precision roller bearings or closely tolerated gas bearings. This arrangement allows precise and, at the same time, cost-effective bearing support.

Problems solved by technology

In total, the encapsulation of the shaft bearings in the common bearing housing further increases the running accuracy of the turborotor, and further reduces the bearing friction.

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